Method of securing a large-diameter tube to a casing underwater

ABSTRACT

This invention relates to a method of securing a large-diameter tube to a casing that is submerged under water e.g. in a river or the sea, and wherein one end of this casing rests on a submerged bed with one end of the tube being driven into this bed within the casing, while the other end of the tube is in free air. According to the invention, concrete is injected from the base of said casing into the annular space defined by said tube and said casing so as to drive the water therefrom. The water located within the said tube is removed after forming a concrete plug at the base of said tube, and after this concrete has set in the annular space, longitudinal openings are made in the interior of the said tube so as to expose the inner surface of said casing through the thickness of the set concrete. The edges of these openings are connected to the inner surface of said casing by means of packing-pieces arranged in the space between said casing and said tube.

United States Patent [191 Loire METHOD OF SECURING A LARGE-DIAMETER TUBE TO A CASING UNDERWATER [75] Inventor: Rene Loire, Paris, France Maritime Hersent, Paris, France [22] Filed: Apr. 30, 1973 [21] Appl. No.: 355,482

[30] 7 Foreign Application Priority Data May 8. 1972 France ..16379 [52] US. Cl. 61/46, 6l/53.58

[51] Int. Cl E02b 1/00, E02d 25/00 [58] Field of Search 61/46, 46.5, 50, 63, 52, 61/53.58

[56] References Cited UNITED STATES PATENTS 2,953,904 9/1960 Christenson 61/46.5

3,121,997 2/1964 Sampson 61/46 3.213.629 10/1965 Manning 61/50 3,512,811 5/1970 Bardgette et al.. 61/46 3,601.999 8/1971 Olsen 61/46 ct. tam

[ 5 7] ABSTRACT This invention relates to a method of securing a largediameter tube to a casing that is submerged under water e.g. in a river or the sea, and wherein one end of this casing rests on a submerged bed with one end of the tube being driven into this bed within the casing, while the other end of the tube is in free air. Accord ing to the invention, concrete is injected from thebase of said casing into the annular space defined by said tube and said casing so as to drive the water therefrom. The water located within the said tube is removed after forming a concrete plug at the base of said tube, and after this concrete has set in the annular space, longitudinal openings are made in the interior of the said tube so as to expose the inner surface of said casing through the thickness of the set concrete. The edges of these openings are connected to the inner surface of said casing by means of packingpieces arranged in the space between said casing and said tube 2 Claims, 3 Drawing Figures METHOD OF SECURING A LARGE-DIAMETER TUBE TO A CASING UNDERWATER The present invention relates to a method of securing a large-diameter tube to a casing under water, in particular where harbour or river installations are concerned.

In general, to connect two members under water, in particular two metal parts, it is necessary to employ special means and trained personnel equipped with diving-suits or diving bells. Several drawbacks result from this, chiefly the slowness of the operation and the high cost.

To overcome these drawbacks, the invention suggests a method, the application of which requires only simple means.

The invention thus has as an object a method of securing a large-diameter tube to a casing submerged under water, one end of which casing rests on a submerged bed, one end of the tube being driven into the underwater floor inside the casing while the other end is in free air.

According to this method, concrete or mortar (these two terms being used interchangeably in what follows) is injected via the base of the easing into the annular space defined by the tube and the said casing so as to drive the water therefrom, and the water situated inside the tube is then removed after a concrete plug has been formed at the base of said tube. Furthermore, after the mortar has set in the annular space, longitudinal openings are made in the inside tube so as to expose the inner surface of the casing, and the edges of the openings are finally connected, by welding for example, to the inner surface of the casing by means of packingpieces arranged in the space between the casing and the tube.

Advantageously, an elastic annular chamber arranged inside the upper part of the casing, before it is submerged, is inflated with high-pressure air and then with concrete, before the mortar is injected into the annular space, so as to grasp the tube and cut off the upper part of the annular space from the surrounding water, the water contained in this space being then expelled through orifices formed for this purpose in the casing and equipped with means for retaining the mortar.

In order that the invention may be more clearly un derstood, reference will now be made to the accompanying drawings which show one embodiment thereof by way of, and in which:

FIG. 1 is a diagram giving a general concept of the method,

FIG. 2 is a detail view showing one phase of the method, and

FIG. 3 is a section along line III-III of FIG. 2.

Referring now to the drawings and in particular to FIG. 1, one end of a tube 1 is driven into the bed e.g. of a river, through a casing 2 which is completely submerged and rests on this bed, while the other end of the tube 1 is in free air. At its upper end, the casing 2 is provided with an annular elastic chamber 7 arranged therewithin. The method consists firstly in inflating this chamber 7 through an orifice 8 thereof with highpressure air, and then in replacing this air with mortar. Then, with the tube 1 and the casing 2 defining an annular space 3, mortar is injected under pressure into this annular space 3 via an opening 4 formed in the base of the casing 2. Other openings formed in the casing 2 and marked 10 in FIG. 1 enable the water expelled by the injection of mortar to escape. These openings 10, which are located :at different levels on the casing 2, enable the build-up of the mortar injected into the space 3 to be checked are are equipped with means for retaining the said concrete.

A concrete plug 5 is next formed within the tube 1 at the base of the latter so as to cut off from the bed the water contained in the tube 1, which is pumped away, and so as to prevent water seeping into this tube through the underwater floor.

Once the tube 1 has been drained, it is possible to make openings 6 in this tube (see also FIG. 2) and thus to expose part of the inner surface of the casing 2 through the thickness of hardened mortar contained in the annular space 3. The edges of the openings 6 are then connected, by welding for example, as shown in FIGS. 2 and 3, to the inner surface of the casing 2 by means of packing-pieces ill between the tube I and the outer 2, the thickness of which is equal to that of the mortar removed.

It will be seen from FIG. 3 that the tube 1 touches the casing 2 at one point of its circumference andthat, at this point, a welded construction is made directly between the tube 1 and the casing 2. The eccentric position of the tube 1 in relation to the casing 2 is due to deformation phenomena inherent. in such structures.

The advantage of such a method resides in the fact that it enables welding operations to be carried out in atmospheric air and thus removes all the disadvantages presented by such operations when carried out under water. Furthermore, the mortar-filled chamber 7 is of advantage in making itpossible initially to hold the tube'l steady transversely in relation to the casing 2, which makes it easier for the mortar to be injected into, and to set in, the annular space 3.

The invention may find significant application in the field of sub-structural work in the sea or in rivers where the setting up of pylons, bridge-piles, etc., with submerged bases is concerned.

I claim:

1. A method of securing a large-diameter tube to a casing submerged under water, one end of which casing rests on a submerged bed, one end of said tube being driven into said bed within said casing while the other end of said tube is above the water and casing in free air, thereby to define a generally annular space between the casing and tube, said method comprising the steps of, injecting concrete at the base of said casing into the annular space defined by said tube and said casing, thereby to drive water out of said space, forming a concrete plug in the base of said tube adjacent said bed, thereafter removing the water within said tube above the concrete plug after the concrete plug has been formed and, after said concrete has set in said annular space, forming a plurality of longitudinally extending openings in said tube along the portion thereof surrounded by said casing to expose the inner surface of said casing through the thickness of concrete in said annular space and, thereafter securing the edges of said openings to the inner surface of said casing with the aid of packing-pieces arranged in the space between said casing and said tube.

2'. A method according to claim 1 including, prior to said step of injecting concrete into said annular space, the steps of placing an annular elastic chamber inside the upper part of said casing before it is submerged, in-

annular space is expelled through orifices in said casing during said injecting step, said orifices being equipped with means for retaining the concrete. 

1. A method of securing a large-diameter tube to a casing submerged under water, one end of which casing rests on a submerged bed, one end of said tube being driven into said bed within said casing while the other end of said tube is above the water and casing in free air, thereby to define a generally annular space between the casing and tube, said method comprising the steps of, injecting concrete at the base of said casing into the annular space defined by said tube and said casing, thereby to drive water out of said space, forming a concrete plug in the base of said tube adjacent said bed, thereafter removing the water within said tube above the concrete plug after the concrete plug has been formed and, after said concrete has set in said annular space, forming a plurality of longitudinally extending openings in said tube along the portion thereof surrounded by said casing to expose the inner surface of said casing through the thickness of concrete in said annular space and, thereafter securing the edges of said openings to the inner surface of said casing with the aid of packing-pieces arranged in the space between said casing and said Tube.
 2. A method according to claim 1 including, prior to said step of injecting concrete into said annular space, the steps of placing an annular elastic chamber inside the upper part of said casing before it is submerged, inflating said chamber with high-pressure air and, then filling said chamber with concrete to grasp said tube and cut off the upper part of the annular space from the surrounding water, whereby the water contained in said annular space is expelled through orifices in said casing during said injecting step, said orifices being equipped with means for retaining the concrete. 